1. Field of the Invention
The invention is a device for transporting film, in particular intermittently, in particular photographic film for motion pictures, in particular unperforated film.
2. Description of the Prior Art
It is known that film which is transported with conventional mechanisms is provided with perforations. A pulldown claw is used to transport film intermittently in a motion picture camera. Unperforated film cannot be transported for motion picture use by conventional transport devices, since there are no perforations for eg. a pulldown claw which is normally used to transport the film intermittently.
It is possible to transport film such as unperforated film using friction on the film surface. It is not possible to transport film accurately intermittently at high speeds using friction alone on the film surface. It is desirable to transport unperforated film because the perforations on the film limit the width of the exposed pictures (frames). Perforating film is expensive because of the close tolerances required between perforations, and microscopic dust caused by the perforating process must be removed during manufacture of the film. Unperforated film therefore allows a wider, larger picture, which means improved picture quality at reduced cost.
It is also known that transporting perforated polyester-based film using conventional mechanisms, eg. with a pulldown claw is possible. However, this is dangerous for the mechanism if the film jams, because polyester film is very difficult to tear.